Spanish police are continuing to investigate last week’s attack in Barcelona, where 15 people died after a van plowed into a crowded walkway along Las Ramblas—the city’s most famous avenue. On Monday police shot dead the man suspected of driving the van: a Moroccan-born, 22-year-old named Younes Abou-yaaqoub. Police believe he was part of a 12-person cell plotting to carry out a series of bomb attacks. Eight of the cell’s members are now dead, four suspected members have been detained. The events of the past week have shocked many in the Barcelona region. On Sunday, thousands of Muslims, including many from Morocco, marched against violence in Barcelona, chanting, "Islam is peace" and "not in my name."